The invention relates to an illuminating station for the manufacture of partially designed areas in one or more layers of a web of sheeting, which station has one or more radiation sources for illuminating the web of sheeting. The invention also relates to a security element having partially designed areas and produced using such an illuminating station.
Laminated sheeting having partially demetallized layers have diverse application possibilities. They can, for example, be used for decoration of the surface of substrates or alternatively for security purposes, eg for securing documents, cards, and bank notes.
GB 2.136.352A describes the use of such laminated sheeting for security purposes, and in this case partial demetallization is achieved by overprinting a thin layer of varnish prior to actual demetallization.
In this case, the laminated sheeting serves as a seal, which is applied to two surfaces. If, following application of the seal, these two surfaces are separated from each other, for example if a package containing a video cassette is opened, this seal is destroyed and thus provides proof of the fact that the package has been opened.
This security product is produced as follows.
A plastics sheet of transparent polyester is printed with a layer of varnish. The layer of varnish thus formed is then embossed with a security hologram. The next step comprises overall metallization of the surface, in which the security hologram has been embossed. Partial demetallization of this surface is then carried out.
Partial demetallization is achieved by printing a protective varnish onto those areas of the thin metal layer which are to remain after demetallization. Then the actual demetallization is carried out, during which process only those areas of the thin metal layer are removed which are not protected by the layer of varnish.
Demetallization is then followed by a washing process. In the subsequent steps, an adhesive layer is applied, and the resulting laminated sheeting is cut into small pieces, each of which can assume the function of the aforementioned seal.
DE 43 29 803 A1 describes a masked projection illuminator for the illumination of objects in a lithography process during the production of semi-conductor elements. A photoresist layer is applied to a quartz wafer in a layer thickness of from 0.1 μm to 1 μm. The quartz wafer is now illuminated through a grid mask. The grid mask comprises a grid mask support and a lattice structure formed thereon. The grid mask support consists of quartz, soda-lime glass, or borosilicate glass. The lattice structure is produced using a photoresist, by the use of a glass layer spattered onto the substrate, or by applying a texture to the rear side of a grid mask support of glass.